烟草野生种eIF4E1-S同源基因的多样性与马铃薯Y病毒抗性分析

[背景和目的]在栽培烟草中,真核生物翻译起始因子(Eukaryotic translation initiation factor 4E1,eIF4E1-S)的缺失或突变能够抗马铃薯Y病毒(Potato virusy,PVY)侵染.为了解烟草野生种eIF4E1-S同源基因的多样性和PVY抗性状况,预测野生种含有抗PVY...

The diversity of eIF4E1-S gene in tobacco wild species and the resistance to Potato virus Y

  Background and Objective  Eukaryotic translation initiation factor 4E1(eIF4E1-S) is tobacco recessive resistance gene to Potato virus Y (PVY). Elucidating the eIF4E1-S diversity and PVY resistance of tobacco wild species is helpful for finding new resistant resources for tobacco breeding.  Methods  In this paper, the eIF4E1 gene cDNA and deduced amino acid sequence of 34 tobacco wild species were determined by eIF4E1 gene amplifying and sequencing, and the phylogenetic tree was constructed by MEGA6 software UPGMA.  Results  In phylogenetic trees, for the four PVY resistant wild species in the Tomentosae group, such as N.otophora, N.setchelli, N.tomentosa, N.tomentosiformis, their resistance to PVY may be related to the evolution from eIF4E1-S to eIF4E1H-T; for the 4 PVY resistant wild species N.benavidesii, N.raimondii, N.cordifolia, N.knightiana in Paniculatae group, their homologous gene amino acid sequence was more consistent with eIF4E1-S than with eIF4E1H-T. The N.glauca, N.africana, and N.noctiflore, which have resistance to 5 PVY isolates (including PVY isolates that can break va resistance) were clustered into a small branch with eIF4E1-S. It was speculated that the PVY resistance of these 3 wild species was independent of eIF4E1 variation and may contain new PVY resistance gene(s). The wild species with PVY resistance, which is different from eIF4E1-S deficiency or variant homologous, is of great breeding value.  Conclusion  According to the diversity of the host factor eIF4E1-S gene used by PVY infection, the probability of the presence of new PVY resistant gene (i.e. not belonging to eIF4E1-S gene loss or mutation) in the tobacco wild species can be divided into high, medium and low third grades. N.glauca, N.noctiflore, and N.africana are more likely to contain new PVY resistant genes than other wild species.